x-display-color-p

x-display-color-p is an alias for `display-color-p' in `faces.el'.

(x-display-color-p &optional DISPLAY)

Return t if DISPLAY supports color.
The optional argument DISPLAY specifies which display to ask about.
DISPLAY should be either a frame or a display name (a string).
If omitted or nil, that stands for the selected frame's display.